1. Field of the Invention
The present invention relates to a system and method for processing continuous integrated queries on both data stream and stored data using a user-defined shared trigger; and, more particularly, to a system and method for processing continuous integrated queries on both data stream and stored data using a user-defined shared trigger for improving overall performance by processing queries on storage data in real-time using a user-defined shared trigger when continuous queries integrating data stream, which is continuously inputted in real-time, and storage data, which are managed in a database, are processed, and reducing a time consumed for processing queries on storage data when continuous integrated queries are processed according to a method for sharing the performance result.
2. Description of Related Art
A ubiquitous computing environment requires a continuous queries process technology for processing data, which are continuously created from a Radio Frequency IDentification (RFID) sensor, Global Positioning System (GPS), diverse sensors including a temperature sensor and a humidity sensor, and diverse application programs, in real-time.
To take an example of a sensor network, the sensor network where light sensor nodes are connected through wireless communication can provide diverse application services for diverse ubiquitous environments including an environment monitoring of an area where people cannot monitor, automating home and office, preventing a crime of home and office, health monitoring, tracing of a mobile object, network monitoring, distribution and circulation, and web log.
Since data processed for diverse application services are continuously created and the quantity of the created data is changed every moment, it is required to process the data in real-time.
That is, in the ubiquitous computing environment, it is increasingly required to develop a data stream management system (DSMS) for processing continuous queries to recognize current status in real-time by continuously transmitting a new result with respect to queries registered by a user or an application.
However, it is difficult to exactly understand and determine the current status only by analyzing the data stream inputted in real-time under the ubiquitous computing environment. When an integrated analyzing process is performed based on history or related information, exact and higher value-added information can be acquired. Accordingly, the data stream management system supports the continuous integrated queries including historical data or related data of a predetermined storage, i.e., a database, as well as data stream inputted in real-time to provide higher value-added information to the user or the application through continuous queries.
In most research and development activities, continuous integrated queries are generally processed by adopting a push-based access method with respect to continuously inputted data stream and adopting a pull-based access method with respect to storage data of the database. In the data stream management system which should transmit the process result of the continuous integrated queries in real-time, a time for processing queries on storage data of the database is longer than a time for processing queries on data stream. Accordingly, when continuous integrated queries are processed, there is a problem that the process performance deteriorates.
That is, the data stream management system according to the conventional technology does not figure out whether the storage data of the database are changed. Accordingly, since the data stream management system adopts a pull-based access method for performing queries after connection with the database is adopted, the time for processing queries on storage data of the database is long and entire queries performance deteriorates.
A related art related to queries performance improvement in a data stream management system will be described in detail.
US Patent No. 2005-0044063 (reference 1), registered on Feb. 24, 2005, discloses a data query system load optimization. When a trigger recognizes the change of the database to optimize a queries process which is repeatedly performed in the relational database, the reference 1 can optimize the repeatedly performed queries in the relational database by re-performing the queries on the relational database in a data process engine and reusing a corresponding queries result in case of the same queries performance. Herein, the trigger senses only the change of the database.
The reference 1 is intended not for continuously inputted data stream, but for the relational database. Also, there is a limit that the queries result is reused only to the same queries.
Also, a technology for processing continuous queries on a data stream and a database based on a tuple inputted in real-time is proposed in an article (reference 2), entitled “Aurora: A New Model and Architecture for Data Stream Management”, VLDB Journal, Vol. 12 No. 2, pp. 120-139, August 2003. The continuous queries processing technology performs an integrated queries process by using a pull-based access method through a connection point based on data of a general tuple concept. Accordingly, the integrated queries on data stream and storage data of the database inputted in real-time can be processed.
In case of the continuous queries processing technology, the technology's scope of application is limited to the data of the tuple concept and the data based on the relational database. Also, since the pull-based access method is adopted for the storage data of the database, there is a problem that performance deteriorates